Many forms of racks, stands, shelves and other such support structures, hereinafter referred to simply as “racks,” have been used for holding articles. Portable racks are used in manufacturing environments to deliver parts to an assembly line for inclusion in or preparation for inclusion in a manufacturing product. Racks are also used to provide uniform storage for articles, parts or components, and further in situations in which transportation and delivery of such items is needed.
Racks are numerous in design, and attempts to improve upon them have been made in the past to suit a variety of needs. One general improvement has been to provide for collapsible racks that may be collapsed, folded or dismantled when not in use, primarily to reduce to the space needed to transport empty racks back to their point of origin. Another general improvement has been to provide for stackable racks that are configured to be stacked vertically on top of other similar racks to utilize space in storage and transportation circumstances.
In both cases, rack designs have been used that provide various advantages and disadvantages to the user. For example, some designs have utilized foldable opposing end frames that, while providing strength and stability, interfere with the rack surface when in a collapsed position. This becomes a disadvantage in manufacturing situations wherein it is preferable for the rack surface of the topmost rack in a vertical stack to be freely accessible to assembly line workers or machines picking parts and components from the rack for utilization on the assembly line. Therefore, it is preferable for racks to be collapsible so that structural components do not interfere with the rack surfaces or the parts stored thereon.
Other racks designs provide collapsibility via dismantling. However, this is not desirable for situations in which quick and safe removal of the rack from an active area is needed, as is the case for assembly lines. Disaggregate rack components may pose a safety hazard if not secured properly in and around assembly line areas, and on board transportation vehicles. Furthermore, separable components generally result in much longer breakdown times for racks. For these reasons, racks with removable components are not favored.
Various hinge or bearing mechanisms have been used to enable folding of leg or frame structures relative to the rack surface or base. It has also been recognized that it is desirous for safety and convenience reasons to avoid bearing designs in which components protrude from the jointed areas which may in turn catch on clothing, machinery, or the articles or parts themselves. To avoid such issues, some designs have utilized a leg or post configuration wherein the leg or support posts slide into or around another structural component of the rack. These designs have often suffered from shaky stability due to loose-fitting parts. Various elaborate mating cuts and welded components have been introduced to increase strength and stability of such configurations, but at the cost of increased production difficulty, expense and complication, and often introduce disadvantages such as protruding components that are undesirable for the reasons mentioned above.
It is therefore an unmet need in the prior art for a collapsible rack that is stackable upon other similar racks when in both the upright and collapsed positions, that has foldable legs that do not interfere with or inhibit access to the rack surface when in the collapsed position, has movable components that remain within the footprint of the rack regardless of position, that has a hinging mechanism that contains no protruding parts and requires no welding or intricate mating surface finishing, that has no separable, removable parts, and that may be quickly collapsed and unfolded in a safe manner.